Purpose
To evaluate the efficacy and safety of cannabidiol (CBD) for the treatment of epilepsy in a real-world setting.

Methods
In this retrospective observational study, we included PwE with epilepsy who received a prescription for CBD between 01.03.2019 and 30.11.2022 and had a follow-up period ≥ 3 months. Participants were evaluated at baseline and after 3, 6, and 12 months. “Responders” were defined as individuals experiencing a reduction in seizure frequency > 30% but < 80% compared to baseline, while “super responders” were those with a reduction ≥ 80%. Adverse events were recorded to assess safety.

Results
Forty-two PwE were included (mean age 36.1±10.9 years; 14 females). In 24 patients CBD was prescribed on-label (Lennox-Gastaut syndrome, n=18; Dravet syndrome, n=5; tuberous sclerosis, n=1), while 18 patients were treated off-label (ring chromosome 20 syndrome, n=1; ring chromosome 17 syndrome, n=1; Lafora disease, n=3; Unverricht-Lundborg disease, n=1; polymicrogyria, n=2; febrile infection-related epilepsy syndrome, n=1; non-lesional focal epilepsy, n=2; developmental and/or epileptic encephalopathy of unknown etiology n=6). The mean number of concomitant antiseizure medications was 3.4 (≥2 for all patients). At 3 months, 10 subjects (23%) were “responders” and 12 (29%) were “super-responders”. Efficacy was sustained at 6 and 12 months of follow-up. Twenty-two patients (52.3%) developed AEs, with drowsiness (36.5%) and diarrhea (9.8%) being the most common. The retention rate was 85.7%, 78.6%, and 71.4% at 3, 6, and 12 months, respectively.

Conclusions
In this monocentric real-world study, CBD was a safe and effective therapeutic option for highly drug-resistant patients, leading to a dramatic reduction in seizure frequency in over one-fourth of them, including off-label indications.